In recent years, there has been a demand from the photographic industry for a silver halide color photographic photosensitive material high in both photosensitive speed and image quality.
To be more concrete, there has been a great demand for the development of a silver halide color photographic photosensitive material having a high photosensitive speed and excellent image qualities such as image-sharpness, image-graininess and interimage effect, along with the increases in opportunities of taking pictures under the severe conditions of dim light such as in the indoor photography or through a telephoto or zoom lens which is apt to produce a hand-blurring, and with making silver halide color photographic photosensitive materials smaller in picture-frame format.
It is, however, difficult to make both of a high sensitization and an image quality improvement compatible.
First, the following layer arrangements have been known to make a photosensitive speed higher. For example, there has been a layer arrangement so-called a normal layer arrangement comprising a red photosensitive silver halide emulsion layer, a green photosensitive silver halide emulsion layer, and a blue photosensitive silver halide emulsion layer each coated in order over a support, wherein the layer substantially sensitive to the same color, among a part or all of the photosensitive silver halide emulsion layers, is separated into two layers, namely, a high-speed silver halide emulsion layer containing ballasted couplers each capable of developing substantially the same hue--hereinafter referred to as a high-speed emulsion layer--and a low-speed silver halide emulsion layer -hereinafter referred to as a low-speed emulsion layer- and the two layers are made adjacent to each other and all the resulting layer are multicoated on.
According to the above-mentioned normal layer arrangement, the following problems have been raised. When exposing the photosensitive silver halide emulsion layers to light, the exposure of one layer closer than the other layers to the support is absorbed by the other layers relatively far from the support and, in addition to the above, in the course of development, it takes a considerably longer time to diffuse a developer.
In other words, the above-mentioned layer arrangement has been disadvantageous to the high sensitization of the green and red photosensitive silver halide emulsion layers each lying lower than the other emulsion layer, that is closer to the support, because of the loss of the exposure and the delay in the development progress.
On the other hand, there have been well-known techniques in which the layer-coating order of photosensitive silver halide emulsion layers has been changed--hereinafter referred to as a reverse layer arrangement--.
For example, U.S. Pat. No. 3,663,228 discloses the following arrangement;
&lt;a&gt; A unit of low-speed emulsion layers, which is comprised of a red photosensitive silver halide emulsion layer, a green photosensitive silver halide emulsion, and a blue photosensitive silver halide emulsion,--the unit is hereinafter referred to as a low-speed RGB layer unit--, such unit is coated over a support in order from the support side,
&lt;b&gt; A unit of high-speed emulsion layers, which is comprised of a red photosensitive silver halide emulsion layer, a green photosensitive silver halide emulsion, and a blue photosensitive silver halide emulsion,--the unit is hereinafter referred to as a high-speed RGB layer unit--, such unit is coated over the above-mentioned low-speed RGB layer unit in order from the support side, so that a double-layered unit arrangement is adopted, and
&lt;c&gt; In the double-layered unit arrangement, each of the high-speed and low-speed RGB layer units is separated by an ND filter--a neutral-density filter--.
As is obvious from the fact that such ND filter is necessarily used therein, this technique has not fully satisfied high image quality performance, because this technique has raised no point at all about any high sensitization.
Next, U.S. Pat. No. 3,658,536 discloses a technique in which an exposure loss is tried to be eliminated from a green photosensitive silver halide emulsion layer which exert a great influence on spectral luminous efficiency, by arranging this green sensitive emulsion layer to the surface side farther from the support. The effect of improving graininess cannot satisfactorily be expected from only a layer-replacing arrangement--a reverse layer arrangement--.
In the meantime, the following techniques have been known as to achieve a high sensitization in a reverse layer arrangement.
&lt;A&gt; Japanese Patent Examined Publication No. 55-34932(1980) discloses the following layer arrangement.
&lt;a&gt; Low-speed red and green photosensitive silver halide emulsion layers,--constituted a low-speed RG layer unit--, are coated each over a support in order from the support side,
&lt;b&gt; High-speed red and green photosensitive silver halide emulsion layers,--constituted a higH-speed RG layer unit--, are each coated over the low-speed RG layer unit in order from the support side, and
&lt;c&gt; As same as in the normal layer arrangement, high-speed and low-speed blue photosensitive silver halide emulsion layers,--constituted a high-low-speed B layer unit--, are each coated over the high-speed RG layer unit.
&lt;B&gt; Japanese Patent Publication Open to Public Inspection (hereinafter referred to as Japanese Patent O.P.I. Publication) No. 61-22294(1986) discloses the following layer arrangement.
In the low-speed RG layer unit of a silver halide color photographic photosensitive material having the above-described layer arrangement &lt;A&gt;, each of the red and green photosensitive silver halide emulsion layers is separated into one layer having a medium-speed and the other having a low-speed.
&lt;C&gt; Japanese Patent O.P.I. Publication No. 59-177551(1984) discloses the following layer arrangement.
A low-speed RGB layer unit and a high-speed RGB layer unit are each coated in order over a support.
&lt;D&gt; Japanese Patent O.P.I. Publication No. 61-72235(1986) discloses the following layer arrangement.
In the above-given Layer arrangement &lt;A&gt;, the maximum color densities each of the red and/or green photosensitive silver halide emulsion layers are within the range of 0.6 to 1.3.
Every silver halide color photographic photosensitive material having the above-mentioned layer arrangement &lt;A&gt;, &lt;C&gt; or &lt;D&gt; may be an effective means for achieving the purposes of making both photosensitive speed and image quality higher, because these photosensitive materials are each arranged with at least one high-speed red photosensitive silver halide emulsion layer between the high-speed green photosensitive emulsion layer and the green photosensitive silver halide emulsion layer having a photosensitive speed lower than that of the high-speed green photosensitive emulsion layer. However, they are still unable to fully satisfy the ultra-high image quality characteristics having been demanded in recent years.